Show Box is not a legitimate software application for watching copyright protected movies.
The movie studios will be able to see your IP address and your COMPLETE viewing history!
(Do you really want the movie studios knowing the types of videos you like?)
You will very likely be sued for copyright infringement.
Those websites that promote and/or distribute Show Box will also be pursued by the movie studios no matter what extent you go through to hide your identity.
It is not worth the trouble!